<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script src="js/vue.js" type="text/javascript" charset="UTF-8"></script>
	</head>
	<body>
	    <div id="box15">
	        <input type="text" v-model="n1">
	        <select v-model="a">
	            <option>+</option>
	            <option>-</option>
	            <option>*</option>
	            <option>/</option>
	        </select>
	        <input type="text" v-model="n2">
	        <input type="button" value="=" @click="show">
	        <input type="text" v-model="n3">
	    </div>
	    <script>
	        var vm = new Vue({
	            el:"#box15",
	            data:{
	                n1:"",
	                n2:"",
	                a:"",
	                n3:""
	            },
	             methods:{
	                show:function() {
	                    switch (this.a){
	                        case '+':
	                        this.n3 = parseInt(this.n1) + parseInt(this.n2);
							break;
	                        case '-':
	                        this.n3 = parseInt(this.n1) - parseInt(this.n2);
							break;
	                        case '*':
	                        this.n3 = parseInt(this.n1) * parseInt(this.n2);
	                        break;
	                        case '/':
	                        this.n3 = parseInt(this.n1) / parseInt(this.n2);
	                       break;
	                    }
	                }
	            }, 
	        })
	    </script>
	</body>
</html>
